The present invention relates generally to means for reducing the nighttime glare from headlights of an oncoming vehicle as experienced by a motorist, and more particularly to an ophthalmic lens system having adjustable, horizontally gradient-tinted lenses which move in unison for user selection of the ideal amount of glare reduction depending on actual driving conditions being encountered.
Methods and apparatus for reducing the glare experienced by a driver due to the headlights of an oncoming vehicle have been the subject of many inventions and much development effort over the years. People worldwide have proposed and provided a wide variety of eyewear and vehicle-mounted devices to address this acute safety problem. While the danger of nighttime glare from headlights has been known for decades, recent developments have made the glare problem more acute. According to the Automobile Club of New York, xe2x80x9c . . . complaints about headlight glare are up, and for good reason. There are more cars and trucks on the road, more sport-utility vehicles (with headlights set at sedan eye level) and an influx of imported high-intensity discharge beams (which cast a discomforting bluish beam). Considering an increasing driver population with eyes growing weak with age or tired from sleep-deprived lifestyles, and nighttime headlight glare is fast becoming a national problem.xe2x80x9d
The AAA Foundation for Traffic Safety, the Federal Highway Administration and automobile manufacturers have recently announced they are searching for solutions. However, they have not found any sure winners yet. It has been determined that where barriers separate opposing lanes of traffic, xe2x80x9cglare screensxe2x80x9d can be effective. The screens are actually a series of steel paddles cemented into the top of the barrier. This type of glare screen works, but they are expensive and can only be used on roads where a barrier exists.
The U.S. Department of Transportation""s National Highway Traffic Safety Administration (NHTSA), in response to numerous consumer complaints about nighttime glare from headlights and auxiliary lights on motor vehicles, has recently sought public comment on possible steps the agency might take to reduce glare. As expressed through complaints to NHTSA, some drivers report that the light from high intensity discharge headlights seem blinding, even though the intensity of such lamps does not exceed federal standards. Some drivers say that xe2x80x9cfog lampsxe2x80x9d are producing troublesome glare and are often used unnecessarily on clear nights. Additionally, some drivers of passenger cars find that the higher-mounted headlights used on SUV""s, pickup trucks and vans to be very glaring.
Description of typical prior art approaches to headlight glare reduction devices and systems may be found in a number of U.S. patents.
U.S. Pat. No. 3,512,880 to Alexander et al. provides a clear and early (1970) teaching of a basic approach of providing glare protective eyeglasses. Each lens of the eyeglass is tinted so as to provide light absorbing portions which gradually increase in absorption while progressing laterally along each of the pair of lenses.
The same basic approach of providing a driver with eyeglasses having a pair of gradient-tinted lenses to reduce headlight glare is found in Australian patent 206,513 to Sandifer. This 1957 patent also suggests the removability of the tinted lenses from conventional eyeglasses. A 1957 French patent to Lenattier also discloses this tinted lens approach, in the 1957 patent No. 1,134,943.
Regarding the feature of adjustability of tinted lenses, two early U.S. patents are of interest. These are U.S. Pat. No. 2,981,956 to Thompson and U.S. Pat. No. 1,723,475 to Esleck. In the ""956 Thompson patent, one of the lens elements of a glare-shielding eyeglass is arranged to be slidably adjustable so as to accommodate different inter-pupillary distances. In the ""475 patent to Esleck, a pair of tinted shields are slidably movable along the upper portion of glare-shielding eyeglasses to shield against strong lights and glare.
Three additional U.S. patents are of general interest for their teachings of various eyeglass arrangements, all directed to reducing glare experienced by a user. These are U.S. Pat. No. 5,428,409 to Silverstein, U.S. Pat. No. 4,859,047 to Badewitz and U.S. Pat. No. 4,828,380 to Cherian.
While each of these prior art devices and approaches functions more or less well, they have not to date provided an optimum solution to the nighttime headlight glare reducing problem, especially in view of the highly variable, real world conditions in which they are required to operate. It is exactly this need that the present invention admirably meets with its specially configured lateral adjustability, which greatly enhances the ability of a user to realize the benefits of the eyeglass arrangement taught herein.
It is therefore a primary object of the present invention to provide an improved headlight glare reducing ophthalmic lens system having lateral adjustment means for optimizing glare reduction.
A further object of the present invention is to provide a specially configured eyeglass arrangement including a pair of gradient-tinted lenses mounted so as to permit lateral adjustability.
A still further object of the present invention is to provide a specially configured eyeglass arrangement wherein the gradient-tinted lens assembly is sized so as to exceed the temple-to-temple distance of its associated frame such that a harmful gap is eliminated as the lens assembly is adjusted to either of its lateral extremes.
A yet further object of the present invention is to provide an improved, laterally adjustable headlight glare reducing, gradient-tinted lens system in the form of personally adjustable eye wear, including at least one side shield and an extended length tinted lens assembly which precludes a gap occurring between the side shield and its closest lens.
In preferred and alternate embodiments, specially configured eyeglass arrangements are disclosed which teach an approach wherein side-to-side adjustability of a pair of gradient-tinted lenses are movable in tandem to allow the user to select the degree of tint (or degree of light attenuation) to be inserted into his viewing path. Via an adjustment means having a predetermined amount of lateral movement, and a slide pin of predetermined dimensions, all of which interconnects a front eyeglass track to a movable beam member carrying the pair of lenses, the relative dimensions of the track and beam may be optimized. To achieve this desired lateral xe2x80x98optimum-tint positionxe2x80x99 adjustment, while avoiding the harmful xe2x80x98gapxe2x80x99 at the lens/side shield interference, the beam member must be greater in length than the track by amount which is fairly quantified. By virtue of this and other adjustments (a bridge/nose pad, etc.), alternate clip-on embodiments may be retrofitted onto conventional prescription eyeglasses to provide the unique glare reduction capabilities according to the present invention.